Thermodynamic analysis of a Kalina power unit driven by low temperature heat sources

In this paper the operation of a reversible Kalina power cycle driven by low temperature heat sources has been studied. A numerical model has been developed to analyze thermodynamically the proposed cycle and to represent it in temperature-entropy and temperature-enthalpy diagrams. A parametric study has been conducted in order to specify the optimum values of the main parameters, i. e. low pressure, condensation and heat source temperature with respect to thermal performance. An improved configuration using a counter-current absorber instead of the conventional condenser (co-current absorber) has been proposed which has significantly higher efficiency and work output. Finally, simple equations have been derived which link the main parameters of the unit with the theoretical thermal efficiency.